sneak one in

To try to have sex with a woman while she is sleeping. Usually this is done to a girlfriend or wife. Otherwise some of the more conservative people could profile this act as rape.

Guy 1: Hey man what are you doing?
Guy 2: Nothing just at my house and my girl is asleep and I really need to bust a nut.
Guy 1: I recommend you sneak one in.
Guy 2: Capital idea!

by Senor Ringpiece August 18, 2009

Sneaking one out

A cheeky wank under cover of the naked eye

I had my hair cut today, the stylist' breasts rubbed against my arm, so I decided to start sneaking one out under the gown

by Angel Rangel November 25, 2013

Sneak up on one cheek

To discreetly fart while in a crowded place.

"If I sneak up on one cheek, hopefully no one will hear me fart."

by creedmoor November 23, 2004